An elbow prosthesis, such as known from EP-A-1 051 954, comprises a humeral component which must reproduce the anatomical trochlea by an artificial trochlea. The positioning of this artificial trochlea with respect to the joint is essential for the elbow thus fitted out to function well.
Up to the present time, surgeons implant the humeral component of an elbow prosthesis by assuming that the position of the axis of bend of the joint can be determined empirically from that of the medullary canal. Now, this is not strictly exact, resulting in defective positioning of the artificial trochlea with respect to the ulnar and radial articular surfaces with which it must cooperate, whether it be the anatomical surfaces or of prosthesis surfaces.